Within a few years of the space shuttle's debut in 1981, the National Aeronautics and Space Administration (NASA) declared the spaceships operational and set about fulfilling an ambitious flight schedule. The space agency hoped to demonstrate that in addition to deploying commercial satellites, flying military payloads, and conducting research, the shuttles were safe enough for ordinary people to fly in.

The first guest astronaut invited into the shuttle's crew cabin was a U.S. senator, Jake Garn of Utah, who chaired a NASA oversight committee. Garn, flying as a "congressional observr," made a seven-day flight in April 1985. While his crewmates dispatched two satellites into orbit and conducted science experiments, Garn took part in an informal quasi-educational "Toys in Space" study.

A twenty-eight-year-old Saudi Arabian prince followed Garn into orbit a few months later. On June 17, 1985, Prince Sultan Salman Abdelazize Al-Saud accompanied a crew of six...